Disneyland is great, but I'm going to give you some insight on how to see the best things in the park:
First get a map! Look up which characters your children are interested in seeing and selectively go to those spots during their viewing time. Don't just walk aimlessly looking for characters or you won't find them. Each character now has a particular location in the park that they are stationed and a schedule by which you can come visit them.
Get a Disney FASTPASS as often as possible. This is a way to avoid the long lines, not like the old days of waiting in line for hours at a time. Again, look at the map and plan out what rides are a must for your visit that day. Get a Disney FASTPASS for the rides that normally are quite the wait. That allows you to go on another ride and then go back to the popular ride and literally cut in line! You can only hold one FASTPASS at a time, so as soon as you use one, go get another! Great rides that are a must: Star Tours, Thunder Mountain, Space Mountain, Splash Mountain, Matterhorn Bobsleds, and Indiana Jones Temple of Doom. The little ones will love all the rides in Toon Town and Fantasyland.
For Dining inside the park there are several great places to eat, but for a great sit down place... eat at the restaurant inside the Pirates of the Caribbean. Here there is good food and a very cool atmosphere!
If you have children this is a must for your visit to Southern California. Spend the money, your kids will talk about Disneyland for years to come and then they will take their own kids... just like you and me!